1 /* 2 * Operations on the network namespace 3 */ 4 #ifndef __NET_NET_NAMESPACE_H 5 #define __NET_NET_NAMESPACE_H 6 7 #include <linux/atomic.h> 8 #include <linux/workqueue.h> 9 #include <linux/list.h> 10 #include <linux/sysctl.h> 11 12 #include <net/netns/core.h> 13 #include <net/netns/mib.h> 14 #include <net/netns/unix.h> 15 #include <net/netns/packet.h> 16 #include <net/netns/ipv4.h> 17 #include <net/netns/ipv6.h> 18 #include <net/netns/dccp.h> 19 #include <net/netns/x_tables.h> 20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 21 #include <net/netns/conntrack.h> 22 #endif 23 #include <net/netns/xfrm.h> 24 25 struct proc_dir_entry; 26 struct net_device; 27 struct sock; 28 struct ctl_table_header; 29 struct net_generic; 30 struct sock; 31 struct netns_ipvs; 32 33 34 #define NETDEV_HASHBITS 8 35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 36 37 struct net { 38 atomic_t passive; /* To decided when the network 39 * namespace should be freed. 40 */ 41 atomic_t count; /* To decided when the network 42 * namespace should be shut down. 43 */ 44 #ifdef NETNS_REFCNT_DEBUG 45 atomic_t use_count; /* To track references we 46 * destroy on demand 47 */ 48 #endif 49 spinlock_t rules_mod_lock; 50 51 struct list_head list; /* list of network namespaces */ 52 struct list_head cleanup_list; /* namespaces on death row */ 53 struct list_head exit_list; /* Use only net_mutex */ 54 55 struct proc_dir_entry *proc_net; 56 struct proc_dir_entry *proc_net_stat; 57 58 #ifdef CONFIG_SYSCTL 59 struct ctl_table_set sysctls; 60 #endif 61 62 struct sock *rtnl; /* rtnetlink socket */ 63 struct sock *genl_sock; 64 65 struct list_head dev_base_head; 66 struct hlist_head *dev_name_head; 67 struct hlist_head *dev_index_head; 68 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 69 70 /* core fib_rules */ 71 struct list_head rules_ops; 72 73 74 struct net_device *loopback_dev; /* The loopback */ 75 struct netns_core core; 76 struct netns_mib mib; 77 struct netns_packet packet; 78 struct netns_unix unx; 79 struct netns_ipv4 ipv4; 80 #if IS_ENABLED(CONFIG_IPV6) 81 struct netns_ipv6 ipv6; 82 #endif 83 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 84 struct netns_dccp dccp; 85 #endif 86 #ifdef CONFIG_NETFILTER 87 struct netns_xt xt; 88 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 89 struct netns_ct ct; 90 #endif 91 struct sock *nfnl; 92 struct sock *nfnl_stash; 93 #endif 94 #ifdef CONFIG_WEXT_CORE 95 struct sk_buff_head wext_nlevents; 96 #endif 97 struct net_generic __rcu *gen; 98 99 /* Note : following structs are cache line aligned */ 100 #ifdef CONFIG_XFRM 101 struct netns_xfrm xfrm; 102 #endif 103 struct netns_ipvs *ipvs; 104 struct sock *diag_nlsk; 105 atomic_t rt_genid; 106 }; 107 108 109 #include <linux/seq_file_net.h> 110 111 /* Init's network namespace */ 112 extern struct net init_net; 113 114 #ifdef CONFIG_NET 115 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); 116 117 #else /* CONFIG_NET */ 118 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns) 119 { 120 /* There is nothing to copy so this is a noop */ 121 return net_ns; 122 } 123 #endif /* CONFIG_NET */ 124 125 126 extern struct list_head net_namespace_list; 127 128 extern struct net *get_net_ns_by_pid(pid_t pid); 129 extern struct net *get_net_ns_by_fd(int pid); 130 131 #ifdef CONFIG_NET_NS 132 extern void __put_net(struct net *net); 133 134 static inline struct net *get_net(struct net *net) 135 { 136 atomic_inc(&net->count); 137 return net; 138 } 139 140 static inline struct net *maybe_get_net(struct net *net) 141 { 142 /* Used when we know struct net exists but we 143 * aren't guaranteed a previous reference count 144 * exists. If the reference count is zero this 145 * function fails and returns NULL. 146 */ 147 if (!atomic_inc_not_zero(&net->count)) 148 net = NULL; 149 return net; 150 } 151 152 static inline void put_net(struct net *net) 153 { 154 if (atomic_dec_and_test(&net->count)) 155 __put_net(net); 156 } 157 158 static inline 159 int net_eq(const struct net *net1, const struct net *net2) 160 { 161 return net1 == net2; 162 } 163 164 extern void net_drop_ns(void *); 165 166 #else 167 168 static inline struct net *get_net(struct net *net) 169 { 170 return net; 171 } 172 173 static inline void put_net(struct net *net) 174 { 175 } 176 177 static inline struct net *maybe_get_net(struct net *net) 178 { 179 return net; 180 } 181 182 static inline 183 int net_eq(const struct net *net1, const struct net *net2) 184 { 185 return 1; 186 } 187 188 #define net_drop_ns NULL 189 #endif 190 191 192 #ifdef NETNS_REFCNT_DEBUG 193 static inline struct net *hold_net(struct net *net) 194 { 195 if (net) 196 atomic_inc(&net->use_count); 197 return net; 198 } 199 200 static inline void release_net(struct net *net) 201 { 202 if (net) 203 atomic_dec(&net->use_count); 204 } 205 #else 206 static inline struct net *hold_net(struct net *net) 207 { 208 return net; 209 } 210 211 static inline void release_net(struct net *net) 212 { 213 } 214 #endif 215 216 #ifdef CONFIG_NET_NS 217 218 static inline void write_pnet(struct net **pnet, struct net *net) 219 { 220 *pnet = net; 221 } 222 223 static inline struct net *read_pnet(struct net * const *pnet) 224 { 225 return *pnet; 226 } 227 228 #else 229 230 #define write_pnet(pnet, net) do { (void)(net);} while (0) 231 #define read_pnet(pnet) (&init_net) 232 233 #endif 234 235 #define for_each_net(VAR) \ 236 list_for_each_entry(VAR, &net_namespace_list, list) 237 238 #define for_each_net_rcu(VAR) \ 239 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 240 241 #ifdef CONFIG_NET_NS 242 #define __net_init 243 #define __net_exit 244 #define __net_initdata 245 #else 246 #define __net_init __init 247 #define __net_exit __exit_refok 248 #define __net_initdata __initdata 249 #endif 250 251 struct pernet_operations { 252 struct list_head list; 253 int (*init)(struct net *net); 254 void (*exit)(struct net *net); 255 void (*exit_batch)(struct list_head *net_exit_list); 256 int *id; 257 size_t size; 258 }; 259 260 /* 261 * Use these carefully. If you implement a network device and it 262 * needs per network namespace operations use device pernet operations, 263 * otherwise use pernet subsys operations. 264 * 265 * Network interfaces need to be removed from a dying netns _before_ 266 * subsys notifiers can be called, as most of the network code cleanup 267 * (which is done from subsys notifiers) runs with the assumption that 268 * dev_remove_pack has been called so no new packets will arrive during 269 * and after the cleanup functions have been called. dev_remove_pack 270 * is not per namespace so instead the guarantee of no more packets 271 * arriving in a network namespace is provided by ensuring that all 272 * network devices and all sockets have left the network namespace 273 * before the cleanup methods are called. 274 * 275 * For the longest time the ipv4 icmp code was registered as a pernet 276 * device which caused kernel oops, and panics during network 277 * namespace cleanup. So please don't get this wrong. 278 */ 279 extern int register_pernet_subsys(struct pernet_operations *); 280 extern void unregister_pernet_subsys(struct pernet_operations *); 281 extern int register_pernet_device(struct pernet_operations *); 282 extern void unregister_pernet_device(struct pernet_operations *); 283 284 struct ctl_table; 285 struct ctl_table_header; 286 287 #ifdef CONFIG_SYSCTL 288 extern int net_sysctl_init(void); 289 extern struct ctl_table_header *register_net_sysctl(struct net *net, 290 const char *path, struct ctl_table *table); 291 extern void unregister_net_sysctl_table(struct ctl_table_header *header); 292 #else 293 static inline int net_sysctl_init(void) { return 0; } 294 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 295 const char *path, struct ctl_table *table) 296 { 297 return NULL; 298 } 299 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 300 { 301 } 302 #endif 303 304 static inline int rt_genid(struct net *net) 305 { 306 return atomic_read(&net->rt_genid); 307 } 308 309 static inline void rt_genid_bump(struct net *net) 310 { 311 atomic_inc(&net->rt_genid); 312 } 313 314 #endif /* __NET_NET_NAMESPACE_H */ 315